Fetal alcohol exposure and adult tumorigenesis.

Adult rats exposed to prenatal alcohol were evaluated for their susceptibility to either hormone- or chemical-inducing tumors. In the first study, rats exposed to prenatal alcohol displayed an increased propensity to beta-estradiol (E2)-induced adenohypophyseal prolactinoma. The susceptibility was manifest as a potentiated increase in anterior pituitary weight as well as in serum prolactin levels after 1 and 3 weeks but not 5 weeks of hormone treatment. Two weeks after withdrawing the E2-implant, the prolactinoma underwent involution and serum prolactin reversed to baseline levels. The high concentrations of serum corticosterone were also reduced but did not return to baseline levels after E2 removal. In the second study, nitrosomethylbenzylamine (NMBA) was utilized to induce esophageal cancer in adult rats. There were no significant differences in tumor incidence or size between the prenatal alcohol-exposed and the pair-fed cohorts. However, the NMBA-treated prenatal alcohol-exposed rats displayed a marked decrease in thymus: body wt ratio as well as adrenal gland hyperplasia. The results suggest that no single mechanism can account for the variable susceptibility displayed by the prenatal alcohol-exposed rats to chemical carcinogens. Some of the observed changes, however, may be attributable to the long-lasting adverse effects of prenatal alcohol exposure on the well-being of the adult host.